The present invention relates to fabric and, more particularly, to architectural fabric that is waterproof, fire retardant, flexible, durable, and aesthetically pleasing.
Architectural fabric is fabric used as a building structure or part of a building structure. It typically provides protection for humans from elements such as wind, sun, and rain. It may be a permanent structure or a temporary one. If temporary, it may be retractable or removable, for example by folding, rolling, or otherwise storing.
There are several requirements for architectural fabric. It must be strong enough to withstand wind and other stresses during assembly and use. It must be flexible and durable, so that it can be folded or rolled and its strength and integrity are maintained over time. It must be UV light resistant. UV light tends to degrade and weaken fabric over time. A fabric that is UV resistant will stand up under this exposure. It should generally be fire retardant and waterproof. It must also be aesthetically pleasing.
A known architectural fabric is a composite consisting of fiberglass fabric coated with PTFE. Although this product has certain desirable qualities, it is not suitably flexible. The fabric thus cannot be used efficiently in applications where convenient removal of the fabric is needed.
Another known architectural fabric has a coating of PVC or acrylic on polyester fabric. These products have flexibility but only limited durability. Unless specially treated, these fabrics are flammable and tend to degrade under UV light. After a certain amount of flexing and UV exposure, these products develop cracks or other imperfections that allow water to penetrate the fabric at the point where it has been compromised.
An architectural fabric that overcomes the deficiencies of the known products is desirable.
The present invention provides an article having (a) a layer of fabric having a first surface and a second surface made of polytetrafluoroethylene fibers; and (b) a first composite comprising (i) a porous PTFE film having interconnected passages and pathways and (ii) a fluoropolymer adhesive, wherein the fluoropolymer adhesive is at least partially contained in the passages and pathways of the PTFE film, the first composite disposed adjacent to the first surface of the fabric. In another embodiment, the invention includes a second composite comprising (i) a porous PTFE film having interconnected passages and pathways and (ii) a fluoropolymer adhesive, wherein said fluoropolymer adhesive is at least partially contained in said passages and pathways of said PTFE film, said second composite disposed adjacent to said second surface of said fabric. The article of the present invention is preferably waterproof, fire retardant, and flexible. Specifically, the article passes a Newark Flex test after 10,000 cycles, after 20,000 cycles, and after 50,000 cycles. It is also preferably an architectural fabric for retractable, temporary, or permanent structures, such as tensile structures, and is adapted to be joined to itself by heat welding.
In another aspect, the present invention provides a method of making an architectural fabric for a retractable, temporary, or permanent structure by:
(a) providing a layer of fabric having a first surface and a second surface and comprising polytetrafluoroethylene fibers;
(b) providing a first layer and a second layer of porous expanded polytetrafluoroethylene membrane;
(c) providing a first layer and a second layer of a terpolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV);
(d) laminating the first layer of THV to the first layer of porous expanded polytetrafluoroethylene membrane to form a first THV/membrane composite;
(e) laminating the first THV/membrane composite to the first surface of the fabric;
(f) laminating the second layer of THV to the second layer of porous expanded polytetrafluoroethylene membrane to form a second THV/membrane composite; and
(g) laminating the second THV/membrane composite to the second surface of the fabric.